Disco-Scopie v2.0 - SCP to extended ADF ?

[Jami]

Hi,

I have recently dumped the original floppy disk of a french utility called Disco-Scopie v2.0 by ESAT Software. I have bought it in 1990 or 1991.



This floppy seems to be standard AmigaOS format howerver there is probably a copy protection : dumping to regular ADF results in a non working floppy image. The loading stops on AmigaOS screen after displaying a date/time... and this title screen never displays :


I had to dump it to SCP file format with my new greaseweazle. This SCP file works unreliably under WinUAE (A500 standard config) :


I saw dlfrsilver has uploaded Disco-Scopie v3.0 to the FTP :
DiscoScopie (F) (Utilitaire Disquette) (1989) [Original v3.0] (Esat Software) (Amiga OCS 512ko) (MFM).zip
Interestingly, this v3.0 dump is an extended ADF format and works fine under WinUAE.

I have already tried to dump my original Disco-Scopie v2.0 floppy directly on my amiga to extended ADF with "rawread -r" and TSGui "Custom" mode => does not work or bypass protection.
I tried to convert the SCP file to extended adf with Keir Fraser's disk-analyse => does not bypass protection.


So I am wondering how can I convert my SCP file to a proper extended ADF, hopefully bypassing the protection ?
I uploaded the SCP file to The Zone.

Any clue I should investigate to achieve that ?


I would like to submit it to Tosec, in the sake of preservation.

[dlfrsilver]

Do something simple : you have a greasleweasle ? Please dump your disk as kryoflux raw dump :

gw read Disk\track.raw --revs=5 --tracks=c=0-83

(Create before that the 'Disk' folder).

Then send me the resulting dump, i will do an IPF, and will make an extended ADF at the same time

[dlfrsilver]

I made a check : the protection is on track 80. Problem: your image doesn't contain anything on this track (checked with Aufit, track is seen as noise or unused).

[Jami]

kryoflux raw dump in the zone

[Jami]

I was curious and opened the kryoflux raw dump I made earlier with Aufit and looked at the 80.0 tack. It looked like noise to my eyes but I have not the knowledge needed

I added 2 more kryoflux raw dumps of this floppy to the Zone.
I have just made them with 2 different HD PC drives connected to my greaseweazle.

I have seen 3 nice peaks on Aufit histogram on the 80.0 track of "Dump_with_old_PC_drive_Mitsumi_1"... don't know if it's relevant. The dump produced by the other drives doesn't have those peaks.



I noticed an odd thing about my fist SCP dump : it works fine under WinUAE when floppy drive speed is set to 800% but does not work reliably when floppy drive set to "100% (compatible)" : it crashes with a blinking "Erreur fatale".

[Keir]

Zoned an unofficial IPF of Disco-Scopie.

Works fine under emulation.

Also writes back to disk using older drives (tested TEAC FD-235F and FD-235HF). Newer drives (tested NEC FD1231M) do not like the long 16us flux times which form part of the key pattern on track 160.

[dlfrsilver]

thanks Keir

[Jami]

Thank you very much Keir !

After pulling your latest disk-analyse commit, I even managed to convert this IPF to an extended ADF that also works reliably under WinUAE.

I got a TEAC FD-235F and will try later on the writing process.

[gizyfr]

Hello
old messages ; As the author of Discoscopie, I can tell you that the original track 80 was protected with the "long track" method, which consists to write data with a rotation speed lower than the regular one. You can write overdata as long track and cannot be copied with a normal floppy disk device. The data can be completely read out with a standard floppy reader (because of the raw MFM sync) and you can check the data length to ensure that this is the original disk.

[dlfrsilver]

Originally Posted by gizyfr

Hello
old messages ; As the author of Discoscopie, I can tell you that the original track 80 was protected with the "long track" method, which consists to write data with a rotation speed lower than the regular one. You can write overdata as long track and cannot be copied with a normal floppy disk device. The data can be completely read out with a standard floppy reader (because of the raw MFM sync) and you can check the data length to ensure that this is the original disk.

Mr Frédéric Sol, welcome aboard

As pointed, a longtrack use normally bitcell in 2us. Here Keir discovered it was not the case (16us).

I use a custom tool to encode flux/stream dumps, and the protection is not seen or recognized at 2us.

[Jami]

@gizyfr : welcome and thanks for this piece of information !

@dlfrsilver : At what stage is the project to include "unofficial" IPFs in the TOSEC ?
It would be great to preserve software like DiscoScopie. I have archived the IPF image made by Keir.
IPF is the most elegant way, isn't it ?

[dlfrsilver]

Originally Posted by Jami

@gizyfr : welcome and thanks for this piece of information !

@dlfrsilver : At what stage is the project to include "unofficial" IPFs in the TOSEC ?
It would be great to preserve software like DiscoScopie. I have archived the IPF image made by Keir.
IPF is the most elegant way, isn't it ?

Yes it is Small file and easy to write

[Crashdisk]

Originally Posted by Jami

@dlfrsilver : At what stage is the project to include "unofficial" IPFs in the TOSEC ?
It would be great to preserve software like DiscoScopie. I have archived the IPF image made by Keir.
IPF is the most elegant way, isn't it ?

This will be done for the next release

[Jami]

Yes ! Thank you !

[dlfrsilver]

Originally Posted by Crashdisk

This will be done for the next release

Merci for that Crashdisk !

[Crashdisk]

It's my turn to thank you!
Also note that a non-SPS IPF games section is currently in progress :-)

[dlfrsilver]

Originally Posted by Crashdisk

It's my turn to thank you!
Also note that a non-SPS IPF games section is currently in progress :-)

Good

[Jami]

I am glad too see Disco-Scopie v2 is the first IPF included in "Commodore Amiga - Applications - [Unofficial IPF]" brand new Tosec DAT !

[dlfrsilver]

That's incredibly cool !

[TCD]

Dump your apps! Let's get them all

And well done to Jami for breaking the ice